t-scores:
0 is normal
-1.0 to -2.5 is osteopenia
-2.5 and below is osteoporosis
How old are you? Most likely it's genetic. I am 34 (very healthy), my hips are -1.4 and my spine is -2.5. I am currently not taking any medication. Just diet and exercise. My sister is ten years older with about the same t-scores when diagnosed and she has seen improvement with diet and exercise alone.
I freaked when I first found out as well, but since have realized it is genetic and not as bad as I had initially suspected. I have to wait a year before I get another scan and see if I am improving.
Good luck